There are hardly any data concerning the vertical micro−distribution of protozoa in water column in cryoconite holes on the glacier surface. Such comparisons can provide insights into the ecology of protozoa. The present research was made on Ecology Glacier (South Shetland Islands, Antarctic); vertical microzonation of c iliates in relation to physical and chemical parameters in cryoconite holes was studied. The density and biomass of protozoans significantly differed between the studied stations (cryoconite holes), with the lowest numbers in the surface water and the highest in the bottom water. The surface waters were dominated by mixotrophic and omnivorous taxa, whe reas the deepest sampling level has shown the increase of the proportion of bacterivore species . Ordination analysis indicated that TN and P−PO 4 can strongly regulate the abundance and species composition of protozoa. The redundancy analyses (RDA) showed that the ciliate communities can be separated into two groups. The first group included species associated with surface water: Halteria grandinella and Codonella sp. The second group included species that are associated with bottom water: Prorodon sp. , Holosticha pullaster , Stylonychia mytilus −complex and small scuticociliates.

Krill population structure was studied in Western Antarctic in austral spring and summer 1986/87. At the end of October and the beginning of November in the waters around Elephant Island the mean krill length was 44 mm and sexually mature specimens dominated. Juveniles were absent. In the Bransfield Strait the mean E. superba length was 43 mm. and males slightly overdominated females. The share of females with spermatophores and of immature females was higher than in the Elephant Island area. Juveniles were also not recorded. Krill was most diversified around Elephant Island in January; juveniles and females with ovaries filled with eggs were recorded. It was found that 84% of krill population was infested by ciliate protozoans (Apostomatida).